NEOPLASMS OF THE CENTRAL NERVOUS SYSTEM

NEOPLASMS OF THE CENTRAL NERVOUS SYSTEM

CLASSIFICATION

Neoplasms may be classified according to localisation and histological features. Histological classification can be sub-divided according to whether the cells are:

Normally present within the cranial or spinal cavity.

Derived from the skull or spine.

Represent cells that are not normal components of the central nervous system, usually representing embryonal components.

Metastatic deposits from elsewhere in the body.

Cells that are normally present within the cranial or spinal cavities include:

Glial cells (astrocytes, oligodendrocytes or ependymal).

Neurons.

Primitive cells of the embryonic neural canal (neuroblasts, medulloblasts and other forms of primitive neuroectodermal tumour, spongioblasts).

Meningeal cells.

Pituitary cells.

Pineal cells.

Schwann cells.

Melanocytes.

Connective tissue cells.

Blood vessels.

Neoplasms of the skull or spine include those derived from bone, cartilage, notochord, and their haemotological components.
Embryonal cells can produce a wide variety of types of neoplasm including neoplasms of mixed cell type and showing variable differentiation.
A wide variety of neoplasms can metastasise to the central nervous system.

Tumours of the Nervous System can be classified as follows : -

Gliomas
Mainly astrocytic: fibrillary, protoplasmic, gemistocytic, pilocytic, anaplastic, glioblastoma multiforme ( may contain a sarcoma-like component), astroblastoma, subependymal giant cell astrocytoma, pleomorphic xanthoastrocytoma.
Mainly oligodendroglial
Ependymoma and subependymoma
Choroid plexus tumours
Papilloma
Carcinoma
Primitive neuroectodermal tumours (PNET) and other embryonic tumours
Medulloblastoma, neuroblastoma, ependymoblastoma, pineoblastoma, spongioblastoma
Tumours containing neurons
Gangliocytoma, ganglioglioma, ganglioneuroma, desmoplastic infantile ganglioglioma, neuroblastoma, dysembryoplastic neuroepithelial tumour, central neurocytoma, olfactory neuroblastoma
Meningioma
Meningothelial, transitional, fibroblastic, psammomatous, angiomatous are the main types
Atypical and malignant
Haemangiopericytoma occurs in the meninges but has now been separated off from the main group of meningiomas.
Nerve sheath tumours
Schwannoma, neurofibroma
Haemangioblastoma
Pituitary adenoma
Craniopharyngioma
Dermoid and epidermoid cysts
Lymphoma and plasma cell neoplasms
Pineal and parapineal tumours
Germinoma, teratoma, pineal parenchymal tumours
Tumours invading the nervous system from a local source
Metastatic tumours